Shrimp resource dynamics and environmental drivers in the Zhoushan fishing ground

This study investigated spatiotemporal variability in the major shrimp resources of the Zhoushan Fishing Ground from 2020 to 2024 and evaluated the development status of the beam trawl shrimp fishery, with the aim of providing a solid scientific basis for future fisheries policy development. Using contemporaneous beam trawl logbook data and remote-sensing–derived environmental variables-dissolved oxygen (DO), sea surface temperature (SST), sea surface salinity (SSS), and chlorophyll-a (Chl.a) concentration—we applied center-of-gravity analysis and generalized additive models (GAMs) to quantify distribution patterns of major shrimp resources and their associations with environmental drivers.The shrimp catch composition was dominated by Metapenaeopsis barbata (23.30%) and Solenocera crassicornis (23.24%). The centers of gravity of these two shrimp resources were located within 30°10′–30°51′N and 124°40′–125°01′E. The centers of gravity exhibited limited variability during 2020–2021 and 2023–2024, whereas they shifted southwestward from 2021 to 2022 and subsequently turned northeastward from 2022 to 2023. Resource density was significantly associated with year, month, longitude, and latitude. For S. crassicornis, the key environmental factors were SST, DO, and Chl.a, with optimal ranges of 14-23°C, 200-250 mmol/m³, and 0-40 mg/m³, respectively. In contrast, M. barbata was primarily influenced by SST and Chl.a, with optimal ranges of 15-30 °C and 30-50 mg/m³, respectively. Overall, shrimp resources remained generally stable from 2020 to 2024, and both catch and CPUE increased markedly following the seasonal fishing moratorium.Extreme weather events and oceanographic variability may substantially affect shrimp distribution and yield. The observed fluctuations in the distributional center of gravity may reflect the combined effects of environmental forcing and fisheries management policies. The CPUE of the two shrimp species showed pronounced spatiotemporal variability, closely related to their reproductive periods and growth cycles. Collectively, the results indicate that SST, Chl.a, and DO are dominant drivers of shrimp distribution and abundance in the Zhoushan Fishing Ground, and that environmental variability together with fisheries management jointly shapes the spatiotemporal dynamics of shrimp resources.